Finding the Third Proportional to 21,215 and 31,818

Step by Step Solution

1. Step 1: Write the proportion equation
   21,215 : 31,818 = 31,818 : x
2. Step 2: Convert to fraction form
   21,215/31,818 = 31,818/x
3. Step 3: Cross multiply
   21,215x = 31,818 × 31,818
4. Step 4: Simplify right side
   21,215x = 1,012,385,124
5. Step 5: Solve for x
   x = 1,012,385,124/21,215
6. Step 6: Final answer
   x = 47,720.25